Electrical switch



July 29, 1947. E. DOUCETTE ELECTRICAL SWITCH Filed Jan. 1 1, 194s EDMUND DOUCETIE INVENTOR.

Patented July 29, 1947 ELECTRICAL SWITCH Edmund Doucette, Newark, N. J.,

assignor to The Daven Company, Newark, N. J., a corporation of New Jersey Application January 11, 1946, Serial No. 640,501

6 Claims.

This invention relates to electrical switches, and more particularly to a switch for use in decade resistors, attenuators, and other instruments such as power switches where the points of contact sweep over a plurality of stationary contacts and which may be used for low or high level circuit.

An object of the present invention is to provide an electrical switch wherein the contact members are yieldably carried by the movable carrying body of the switch for yielding movement relative thereto to provide a firm, positive contact at all times with the stationary contacts with which they co-operate, irrespective of wear or unevenness of the mounting of the stationary contacts.

Another object of the present invention is to provide a switch structure which is so constructed and designed that the individual switches may be assembled in complete units and attached as complete units to the carrying bar, and further to provide a switch structure which, due to its compactness and arrangement of parts, readily lends itself to multiple mounting on a carrying bar.

A further object of the present invention is to provide a switch as specified which is simple in construction, embodying a minimum number of parts and which is so constructed and arranged as to prevent accidental displacement of the parts during use.

The switch of the present invention is particularly adapted for use in attenuators, as disclosed in my co-pending applications Serial No. 590,265, filed April 25, 1945, and Serial No. 579,- 829, filed February 26, 1945, although it is equally useful in connection with other similar instruments.

With these and other objects in view, as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing an electrical switch of a preferred form embodying the invention, and the features forming the invention will be specifically pointed out in the claims,

In the drawings:

Figure 1 is a plan view of a switch structure showing it associated with the stationary contacts of an attenuator or similar instrument;

Figure 2 is a plan view of the switch structure showing it assembled;

Figure 3 is an edge elevation of the switch structure having the carrying arm partly broken 2 away to show one of the switch contact elements or units in side elevation;

Figure 4 is an end elevation of one of the switch contact units;

Figure 5 is a bottom plan of one of the switch contact units;

Figure 6 is a longitudinal section through one of the switch contact units taken on the line 6-6 of Figure 5;

Figure 7 is a cross section through one of the switch contact units taken on the line 1'l of Figure 5;

Figure 8 is a perspective view of the carrying body of the switch contact unit;

Figure 9 is a perspective view of the cover plate of the carrying body; and

Figure 10 is a perspective view of one of the contact elements.

Referring more particularly to the drawings, I indicates the contact-carrying plate or electrical instrument such as a decade resistor, attenuator or the like which carries a plurality of rings of stationary contacts indicated respectively at 2, 3, and 4. These rings of contacts 2 and 3 and the contact ring 4 are concentric of the axis of the shaft 5 which carries the carrying bar 6 of the switch structure proper. The carrying bar 6 is constructed of insulating material and is attached to the shaft 5 in any suitable manner so that it will be moved about the axis of the shaft 5 upon rotation of the shaft. The carrying bar 6 carries any desired number of switch contact units generically indicated at 1, two of which are shown in the drawings, but it is to be understood that any desired number required for the service to be performed may be carried by the carrying bar 6.

All of the switch contact units in construction and they include a carrying body 8. The carrying body 8 is made of flat sheet metal and it has a bottom 9 and sides II! which extend at right angles to the bottom 9. Horizontally extending attaching wings or extensions I I are formed upon and extend at right angles to the sides I0. The attaching wings or extensions I I are provided with openings I2 for receiving rivets indicated at l3 for attaching the complete assembled switch contact unit to the carrying bar. The sides I0 of the carrying body 8 extend beyond the ends of the bottom =9, as clearly shown in Figure 8 of the drawings. A plurality, that is, two or, if desired, more than two U-shaped contact members I4, as shown in perspective of Figure 10 of the drawings, are carried by the carrying body 8, and the legs l5 1 are identical of these contact members extend through the space at the ends of the bottom 9, projecting outwardly from the bottom 9, as clearly shown in Figures 3, 4, 6 and 1, for engagement with the contacts of the rings 2 and 3 of the ring contact 4, dependin upon their position on the carrying bar 6. A bowed fiat spring it engages the inner surface of the cross bar of the U-shaped contacts 14 for urging the contacts outwardly; that is, for urging the ends of their leg l5 into yieldable engagement with the contacts of the contact head or plate i. The U-shaped members H! and the spring l6 are nested in the troughlike recess of the body 8, as is clearly shown in Figures 6 and '7 of the drawings, and they are held in place by a cover plate IT.

The bowed spring l5 flatten off at each end, as shown at l6, so as to permit the edge of the springs to glide smoothly over the U-shaped member with which it is in engagement, thus providing easy movement of the spring and U- shaped member and providing natural spring tension when the switch is placed in position and pressed down in the carrying body 8 to give the required pressure on the U-shaped member for engagement with the contacts 2 or 3.

The springs 8 maintain an even pressure on the U-shaped members l4 so as to insure the multiple point contact with the contacts 2 or 3 which is so desirable in electric circuits.

While flat bowed springs are shown in the drawings, it is to be understood that spiral springs or any suitable shaped springs may be employed without departing from the spirit of the present invention.

The cover plate i! has depending ends i8 which fit between the projecting ends of the sides l'd of the body 8 for preventing longitudinal movement of the inverted U-shaped contacts l relative to the body, while the main body plate of the cover plate ll engages against the attaching wings or extensions ii and extends over the trough-like recess in the body 8 for confining the contacts M and their springs i6 within the body.

The cover plate ll is provided with openings is which receive the rivets l3 theretluough so that the rivets l3 serve the dual purpose of holding the various parts of the contact unit structure I in assembled position, as well as for attaching the assembled contact unit to the carrying bar 6.

In Figure 6 of the drawings, the parts are shown as slightly extended for the purpose of clarification.

The carrying bar 8 is provided with slots, as indicated at 29, which extend inwardly from the ends of the carrying bar, and these slots are just wide enough to receive therebetween the sides ID of the carrying member 8 so that by the accurate cutting of the slots 20, the contact units will be properly positioned on the carrying bar by the mere sliding of them into the slots 20 with the attaching extensions H engaging against the outer surfaces of the carrying bar, and thus the switch structure may be easily, quickly, and accurately assembled.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that they may be widely modified within the invention defined by the claims.

What is claimed is:

1. A switch structure for use with an electrical instrument including: a plurality of concentric circles of stationary contacts; said switch including a carrying body, a plurality of inverted U- shaped contact members carried by said carrying body, and springs between said inverted U-shaped members for said body to yieldably maintain said inverted U-shaped members in spaced relation and urge the ends of their legs in contact-engaging position; said carrying body open at its top to facilitate assembly of the inverted U- shaped contacts and their associated springs; said carrying body having its bottom cut away at its ends to permit extension of the legs of the inverted U-shaped contours to project from the carrying body; and a cover plate on said body for confining said inverted U-shaped contours and springs within the body.

2. A switch structure for use with an electrical instrument including: a plurality of concentric circles of stationary contacts; said switch including a carrying body, a plurality of inverted U- shaped contact members carried by said carrying body, and springs between said inverted U-shaped members for said body to yieldably maintain said inverted U-shaped members in spaced relation and urge the ends of their legs in contact-engaging position; said carrying body open at its top to facilitate assembly of the inverted U-shaped contacts and their associated springs; said carrying body having its bottom cut away at its ends to permit extension of the legs of the inverted U-shaped contours to project from the carrying body; a cover plate on said body for confining said inverted U-shaped contours and springs within the body; and depending end projections on said cover plate for closing the ends of said carrying body.

3. A switch structure for use with an electrical instrument including: a plurality of concentric circles of stationary contacts; said switch including a carrying body, a plurality of inverted U- shaped contact members carried by said carrying body, and springs between said inverted U-shaped members for said body to yieldably maintain said inverted U-shaped members in spaced relation and urge the ends of their legs in contact-engaging position; said carrying bod open at its top to facilitate assembly of th inverted U-shaped contacts and their associated springs; said carrying body having its bottom cut away at its ends to permit extension of the legs of the inverted U- shaped contours to project from the carrying body; a cover plate on said body for confining said inverted U-shaped contours and springs within the body; said carrying body having attaching extensions thereon; and said cover having portions thereof for engagement with said attaching extensions whereby when the switch unit is attached to a carrying bar said cover and carrying bar will be attached one to the other,

4. In a switch structure for use with an electrical instrument including a, plurality of concentric circles of stationary contacts, a carrying bar provided with a cut out portion extending inwardly from one end thereof, a contact switch assembly unit including a carrying bod having a bottom and sides, the ends of said sides projecting beyond the ends of said body, an inverted U- shaped contact carried by said carrying body and having its legs projecting beyond the bottom of the carrying body through the space between the ends of the bottom and sides, a spring engaging said U-shaped contact for urging its legs into contact-engaging position, and a cover plate for engagement with said body to confine said inverted U-shaped contact and spring in the body.

5. In a switch structure for use with an electrical instrument including a plurality of concentric circles of stationary contacts, a carrying bar provided with a. cut out portion xtending inwardly from one end thereof, a contact switch assembly unit including a carrying body having a bottom and sides, the ends of said sides projecting beyond the ends of said body, an inverted U- shaped contact carried by said carrying body and having its legs projecting beyond the bottom of the carrying body through the space between the ends of the bottom and sides, a spring engaging said U-shaped contact for urging its legs into contact-engaging position, a cover plate for engagement with said body to confine said inverted U-shaped contact and spring in the body, said carrying body having attaching extensions thereon, and said cover having portions thereof for engagement with said attaching extensions whereby when the switch unit is attached to a carrying arm said cover and carrying body will be attached one to the other.

6. In a switch structure for use with an electrical instrument including a plurality of concentric circles of stationar contacts, a carrying arm provided with a cut out portion extending inwardly from one end thereof, a contact switch unit inserted in said cut-out portion and including a carrying body shaped to slip into and fit snugly in said out out portion, said carrying body including a bottom and sides, said sides extending beyond the ends of said bottom, a plurality of inverted U-shaped contacts nested within said body between said sides, a plurality of bowed springs engaging said inverted U-shaped contacts for urging the legs of the contacts outwardly into stationary contact-engaging positions, a cover plate including projecting ends for closing the end portions of said carrying body, said carrying body having laterally extending attaching extensions formed thereon, said cover plate having portions for fiatwise engagement with said attachin extensions, said cover plate and attachin extensions provided with rigid receiving openings whereby the cover plat and carrying body are attached one to the other and to the carrying arm,

EDMUND DOUCETTE.

REFERENCES CITED UNITED STATES PATENTS Name Date Maier Nov, 25, 1941 Number 

